Bulk material can be moved to a location of use or storage in a transport container such as a tractor-trailer. When the transport container arrives at the location, the bulk material is unloaded from the transport container for storage or processing. A conveyor system may be used to aid the unloading process by moving material from the transport container into a storage or processing area.
Biomass is an example of bulk material. Biomass comprises plant matter that can be suitable for direct use as a fuel/energy source or as a feedstock for processing into another bioproduct (e.g., a biofuel such as cellulosic ethanol) produced at a biorefinery (such as an ethanol plant). Biomass may comprise, for example, corncobs and stover (e.g., stalks and leaves) made available during or after harvesting of the corn kernels. In order to be used or processed, biomass will be harvested and collected from the field and transported to the location where it is to be used or processed. Biomass (such as corncobs and stover) may be collected and stored in piles at the edge of the field. The piles of biomass are then collected and transported from the field to the location of intended use or processing.
In order to provide biomass to a lignocellulosic ethanol process, biomass may be delivered (e.g., by a truck and trailer or by other similar transportation means) to a storage location near the plant incorporating the process. Biomass may be stored in piles at the plant or at another location. In order to pile the biomass delivered to the storage site, a conveyor system may be used.
Bulk materials such as biomass when stored outside will realize material losses due to precipitation intrusion into the storage pile. Precipitation intrusion into the pile is enhanced when there are peaks and valleys or other surface irregularities on the pile which collect precipitation. Precipitation that collects on and penetrates the pile may increase the rate of decomposition of the bulk material resulting in material losses.
In conventional conveyors, conveyed material is dropped off the end of the belt, where gravity causes it to fall vertically onto the pile. This vertical fall results in a concentration of material below the end of the belt. When the height of the pile reaches the height of the end of the belt, the conveyor is moved in a longitudinal direction away from the pile so that material can continue to be added to the pile. This movement results in a pile having peaks and valleys as the conveyor is moved and material is added to the pile. These surface irregularities can be further enhanced as the bulk material in the pile settles over time.
Conventional conveyors typically receive material from a single trailer at any one time at their receiving systems. With the ability to receive only a single trailer, such conveyors are not able to operate and process material between loads, i.e. the time during which one trailer has been emptied and another trailer is positioned for unloading.
It would be advantageous to provide for a belt conveyor apparatus for movement of biomass from the transport container to a storage area. It would also be advantageous to provide for a belt conveyor apparatus that forms a biomass pile that has a substantially crowned, continuous (e.g. smooth) outer surface. It would be further advantageous to provide for a conveyor that has a high capacity for unloading bulk material in a continuous manner.